Electrical alarm for letter-boxes



(No Mdel.)

L. BHRLIGH. ELEGTREC-AL ALARM EUR LETTER BOXES. Nm 329,294. Patented 001;. 27, 1885.

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UNITED STATES PATENT OEEICEo LEO EHRLIOII, OF ST. LOUIS, MISSOURI.

ELECTRICAL ALARM FOR LETTER-BOXES.

SPECIFICATION forming part of Letters Patent No. 329,294, dated October 27, 1885.

Application filed May 12, 1885.

To all whom it may concern:

Be it known thatl, LEO EnELTci-r, a citizen of the United States, residing at St. Louis, in the county of St. Louis and State of Missouri, haveinvented certain new and useful Improvements in Electric Alarms for Letter-Boxes, of which the following is a specication, reference being had therein to the accompanying drawings.

My invention relates to improvements in electric alarms adapted especially to letterboxes, and is designed to produce a safeguard against the improper entrance into the said letter-box by giving notice at acentral office of the opening 'of the box, which notice would be in the nature of an alarm were the box tampered with by improper persons, as the carrier always opens the box at stated intervals, in accordance with the usage of the Post Office Department.

In describing the device reference is had to the annexed drawings, in which Figure l shows a perspective View of the box with the alarm mechanism attached, and Fig. 2, a plan view of the bottom of the box, showing the alarm mechanism.

To eifectually prevent burglarizing, the electric appliance adapted to give an alarm at the central office is secured in the bottom of the box, and consists of a metal strip, A, having a short right-angle extension, B, at one end, and a short strip, C, parallel with it. The strip C has a spring end projecting over the extension B. A short lever, D, is pivoted to the box, and has one end adapted to engage with the under side of the spring end of the strip O, as shown. On the door is an arcshaped strip, E, passing through a guide, F, on the box, and when the door is closed engages with the free end of the lever and raises the end of the strip C. By means of wires G the strips have connection with the central office. When the door is closed, the strip C Serial No. 165,Q29. (No model.)

is raised from the extension B, and thus the circuit is broken, while when the door is opened from any cause the parts contact and the circuit is closed, an alarm or other indication being thereby given at the central office that the box is opened. rPhe alarm will of course ring when the carrier opens the box to obtain the mail deposited there, but as the exact time at which he will reach any specified box is known at the central o'l'tice, the official in charge will know that the box is being opened by the proper person. The alarm also acts as an automatic watch7 on the carriers. To more effectually protect the perfect operation of the box, the wires may pass inside the post to which it is secured, and thence by an underground passage to the ccntral office, thus preventing the cutting of the wires for criminal purposes.

rIhis device is applicable to any letter-box.

I claimrlhe combination, with a letter or mail box, of anelectric alarm apparatus consisting of an arc-shaped strip secured to the door of the box and guided on the side of said box, a lever pivoted to the side of the box on the interior and having one `end in normal engagement with the arc strip, a strip having one end resting on the other end of the lever and the other end secured to the box and engaging or connecting with an electric wire, and a strip having one end secured to the box and connected to an electric wire and the other end provided with an angle-extension resting under the other strip secured to the box, substantially as and for the purpose specified.

In testimony whereof I affix my signature in presence of two witnesses.

LEO EHRLIOH.

'Vitnesses:

GHAs. T. DEMrsEY, F. E. G. CARE. 

